Abstract

The carbon balance of forested ecosystems are fundamentally linked to cycles of disturbance and recovery. Two of the most extreme natural disturbances are tropical cyclones and Amazon forest fires. While an average of more than 80 tropical storms and hurricanes occur per year, the number, severity, and impacts of these storms varies through time and may be increasing, while the committed carbon emissions from a single large storm such as Katrina can be as large as the net annual carbon sequestration of U.S. forest trees. Forest fires are a growing concern too, particularly in the sensitive Amazon region where they potentially compound the risk of forest die-back from climate change. The overall science goal of this project is to understand how altered natural disturbance rates could affect the carbon balance of terrestrial ecosystems, and as a consequence, the development strategies designed to mitigate against future climate change. In particular, we address two major science questions: 1) How could potentially altered disturbance rates from tropical cyclones and Amazonian fires affect vegetation, carbon stocks and fluxes, and the development of climate change mitigation strategies? 2) How does remote sensing data quantity and quality constrain model projections of the effects of altered disturbance rates on vegetation, carbon stocks and fluxes, and the development of climate change mitigation strategies? These science questions are addressed through four linked objectives: 1) remote sensing and modeling forest disturbances (tropical cyclones and Amazonian fires); 2) assess the consequences of forest disturbances in integrated assessments; 3) link ecological and socio-economic models addressing forest disturbance; and 4) quantify the implications of forest disturbances for future satellite missions and Earth System models.